1811440 - Fix BodyStream to support actual Bring-Your-Own-Buffer(BYOB)

Status: RESOLVED FIXED

(Core :: DOM: Networking, enhancement, P2)

Description

[Kagami Rosylight [:saschanaz] (they/them)]

Currently BodyStream just enqueues things by creating a new Uint8Array: https://searchfox.org/mozilla-central/rev/7426a35738cd542b9488c7b67f4f6d21edfeda0a/dom/base/BodyStream.cpp#435

Instead, it should write into [[byobRequest]] view when available to reduce copy. The behavior won't be web-visible, it's more for better performance by skipping copy into a new Uint8Array and then again into byob buffer.

Comment 1

[Kagami Rosylight [:saschanaz] (they/them)]

Attachment: Bug 1811440 - Part 2: Implement pull-from-bytes algorithm for InputToReadableStreamAlgorithms r=smaug

Comment 2

[Kagami Rosylight [:saschanaz] (they/them)]

(Preparing release note request early)

Release Note Request (optional, but appreciated)
[Why is this notable]: It provides more performant way when reading stream from Fetch and WebTransport
[Affects Firefox for Android]: Yes
[Suggested wording]: This release now supports proper BYOB readers on Fetch and WebTransport, which allows devs to prepare their ArrayBuffer so that it can be reused for read requests and thus saves memory allocation. .getReader({ mode: "byob" }) on Fetch and WebTransport streams was supported on previous releases but without true BYOB support as new memory allocation still occurred internally.
[Links (documentation, blog post, etc)]: (None)

Comment 3

[Kagami Rosylight [:saschanaz] (they/them)]

Attachment: Bug 1811440 - Part 1: Rethrow error from InputToReadableStreamAlgorithms::WriteIntoReadRequestBuffer r=smaug

... instead of handling it within itself, which makes the error handling story complex.

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/d61e3f16a3fa
Part 1: Rethrow error from InputToReadableStreamAlgorithms::WriteIntoReadRequestBuffer r=smaug
https://hg.mozilla.org/integration/autoland/rev/d3f82b964829
Part 2: Implement pull-from-bytes algorithm for InputToReadableStreamAlgorithms r=smaug

Comment 5

[Iulian Moraru]

https://hg.mozilla.org/mozilla-central/rev/d61e3f16a3fa
https://hg.mozilla.org/mozilla-central/rev/d3f82b964829

Comment 6

[Dianna Smith [:diannaS]]

Added to 116 nightly release notes https://www.mozilla.org/en-US/firefox/116.0a1/releasenotes/